Studies planned for the coming year include examination of the nature and extent of sickle cell hemoglobin (HbS) aggregation in oxy and deoxy irreversibly sickled cells (ISC's) using pulsed nuclear magnetic resonance (NMR) techniques. Comparison with ordinary sickle cells and normal erythrocytes will be made. Ghost-free solutions of HbS derived from the ISC's will also be examined in an exploration of the role of the membrane in maintenance of ISC cell shape. Studies on the nature of water interacting with normal adult hemoglobin (HbA) and HbS in both the oxy and deoxy state in normal erythrocytes and sickle cells has been in progress for over a year. The studies will now focus on solutions of HbS, which is being chromatographically prepared, so that complications in interpretation due to the presence of HbA, HbF, and HbC can be avoided. Since our investigations have shown that the value of the water proton rotating frame spin-lattice relaxation time (T1 Rho) is a sensitive indicator of the extent of HbS microtuble formation, we will explore the use of T1 Rho measurements for assaying the potency of various chemical reagents in preventing microtuble assembly. Among the reagents to be explored initially are cyanate, dichloromethane, and dimethyl adipimidate.